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Marantz 10B (1964, $650, photo, schematic1, schematic2, brochure1, brochure2, brochure3, brochure4, brochureA, brochureB) search eBay
By most accounts, the FM-only Marantz 10B has great sound on strong signals and a tendency to require repair rather frequently in order to continue to perform at its peak. Our panelist Jim says, "I've borrowed two different Marantz 10Bs and both only played in mono because the opto couplers went bad" (cary300b@hotmail.com sells new replacement opto couplers, but we don't know him personally). Jim adds, "I have heard many accounts of 10B's laid to the side, sold as problematic or even enshrined as objects of audio art (in Japan). Two I've seen in Dallas were kept in a garage because they 'aren't working right.' One other was in an apartment closet because it only played in mono. I listened and tinkered with that one for a month but didn't know what was wrong and couldn't help the guy. I tried different tubes and cleaning it." The 10B's claimed selectivity specs (150 dB for alternate channel and 42 dB for adjacent channel, which would be on a par with the MR 78 or T-9090II if only they were true), are awesome. However, if you're looking for a top tuner and not just a collector's item, don't buy a 10B without reading the discussion in our FMtuners group beginning here, and here (where our knowledgable contributor Brian L. calls the 150 dB spec "horse manure").

Former Stereophile reviewer Don Scott said, "Try a 10B on a station that has three subcarriers and join the Audobon Society," meaning its poor SCA rejection makes it prone to "birdies" (whistles or heterodynes), and as part of a 1987 review for Stereophile Don estimated one particular 10B's selectivity at a very pedestrian 70 dB alternate, 10 dB adjacent. Our contributor Peter W. says, "YES, it sounds wonderful. YES, it is a gorgeous tuner with very high production and build values. But it is a mediocre performer by the standards of even five years after its introduction, much less what is available today." Ben Blish of classic-audio.com commented, "My 2130 eats my 10B for lunch"! Our contributor Al points out that "Marantz never, ever published the IHF selectivity of the 10B. The 150 dB and 42 dB figures are (as they describe them) IF filter response curves. They are probably accurate, but are meaningless in real world use. As per Marantz, the 10B's IF response is down about 152 dB at 400 kHz. However, a modulated carrier has a sideband at about 320 kHz. Here, the 10B's response curve is down by about 109 dB. This is the alternate channel selectivity the 10B's IF could produce except for one problem; the 10B's spurious rejection is only 100 dB. Therefore, I believe the maximum IHF selectivity for the 10B would be around 100 dB alternate channel. What is found in the field could be even less. The adjacent channel IHF selectivity should be almost nil (passband too wide)."

Our contributor John Byrns summarizes: "The IHF spurious response measurement is largely irrelevant in any halfway decent tuner [because it] uses a single interfering signal, while the predominant spurious response problem in better tuners is third order IM [intermodulation or "IP3" - Editor] which requires the use of two interfering signals to measure. The Marantz 10B is the poster boy for third order IM problems. Its selectivity is more than adequate for most uses, but its third order IM performance is abysmal, creating interference problems at signal levels far lower than those used in the IHF selectivity test." Our contributor David Rich adds, "Two stages of RF give very good sensitivity but poor IP3. You need sensitivity indoors but the IP3 kills performance when you put big signals at the input. This is especially true when the antenna input is single-tuned. The 10B has two RF stages but tubes have a lot more headroom. I understand Sid Smith later said that it was a mistake to use two stages." Our contributor Peter K. has a suggestion for those who do own a 10B: "The audio of the Marantz 10B will improve a lot by removing the optoswitch from the stereo signal path, replacing it with resistors and connecting the mono optoswitch between left and right channel after the resistors." Our contributor Gene says, "I own a stock Sansui TU-717 and a 10B. Yes, the 10B kicks the 717's butt, sound-wise, and I REALLY love the o'scope." And our contributor Paul explains in our FMtuners group what he observes on the 10B's oscilloscope.

John Byrns adds: "With respect to the 150 dB alternate channel selectivity, the issue is whether Marantz actually measured that number, or if they got it by some sort of calculation. In any case, I doubt Marantz had a spectrum analyzer with the capabilities of modern instruments. I did some calculations to see what was going on with this number, and if I recall correctly, even if you had perfect test equipment, if you made the measurement using the IHFM standard, you would have to pump so much power into the antenna circuit of the 10B that the tuner would be reduced to a ball of molten metal. In reality it's mostly academic, as I don't believe there is any possible way to make use of 150 dB of alternate channel selectivity; considerably less will fill any real-world need. The real selectivity issue with the 10B [as with any tuner - Editor] is the adjacent channel selectivity, and by this measure I don't believe the 10B is a particularly stellar performer. Another issue with respect to the 10B IF filters is exactly what sort of filters they really are. In advertisements for the 10B, Marantz claimed they were Butterworth filters, but Butterworth filters are not the most phase linear, as is required for superlative stereo, so some people today claim that the 10B IF filters were not Butterworth, but were a more phase linear design. It's hard to know what the truth is about the 10B IF filters, or if this is simply an attempt to make the 10B look better in the light of history. The filter type is relevant to the adjacent channel selectivity because generally the more phase linear filters are less selective. Another possibility is that the filters in some 10Bs could have been aligned for a Butterworth characteristic, and at other points in the history of the tuner the factory may have aligned them for a more phase linear response, making both versions of the story true." [JR]

Sale prices for the 10B on eBay have defied the general trend of lower prices during the 2008-2009 recession. Many nice examples have sold for more than $3,000, with highs of $3,650 in 3/08 and $3,700 in 6/08 for one with a rack-mount faceplate. Garden variety 10Bs can sell for $1,500-2,500.

Marantz Model Twenty search eBay
The FM-only 20 and 20B look identical and, according to our contributor Charles K., the original nameplate is not always a reliable way to know which tuner you have. Here's his explanation of how to tell them apart: "The difference between the units is in the front end. The 20 used the same passive tuned RF/balanced mixer style design as in the 10. The 20B used a new active design with a tuned RF amp stage which got AGC feedback from the IF section. Problem is, the front end is in a stainless steel housing which is a bear to open up to try and tell the difference. You CAN tell by looking at the rectangular IF section enclosure which is the long, rectangular, stainless steel box mounted behind the black cover which houses the RF stage. This box has RCA connectors (with cable) at each end which is signal in and out. On the right-hand side of the box are two feedthrough posts which are + and - 12 volts for power to the IF section. If the tuner is a 20B, it has a single feedthrough post on the left-hand side for the AGC return. There is no post on the left hand side if the tuner is a Model 20. According to the spec sheet, the B version is slightly more sensitive. I've never had the luxury of having both versions side by side so I can't make any subjective comments, but I like the fact that the 20 mirrors the 10 design more closely." Our contributor David Rich confirms Charles's observations: "In the Marantz 18 and 20 no RF stage at all is used and the mixer is passive. That proved to make the sets unusable with indoor antennas, so they added on RF stage in the 19 and 20B (it is the only difference between the tuners)."

Our contributor Al compares the 20 and 20B to the 18 and 19 receivers: "The 20 is basically the tuner section of the 18. The 20B is virtually identical to the tuner section of the 19. The differences between the 20 and 20B appear to be only the inclusion of a dual gate MOSFET RF amp at the input of the 20B and replacing a bipolar first IF amp with an FET on the 20B. The 20/20B and 19 have antenna attenuators which the 18 lacks. Without the attenuators these all have mediocre strong signal handling. The 18, predecessor to the others, had some problems which seem to have been corrected in the others. A scope drive transistor tends to burn out on the 18. The MPX board on the 18 was made with an error requiring jumpers. This fix appeared even on late production 18s. The circuit boards in the 20/20B and 19 for the IF, limiter, MPX all look identical. The tuners have output buffers that the receivers obviously don't have. This could potentially be a source of a difference in sound, but I couldn't definitively detect any. The tuners, 20 and 20B, appear to have more sharply tuned IF sections than the receivers. I guess they had more tweaking on the setup bench. To my biased ears these pieces all sound wonderful." The 20 and 20B, like the 10B, have a high-blend setting on the Mode switch (stereo/high blend/mono) which blends the highs to mono to help with noise. The Model Twenty usually sells for $500 to $725 on eBay if its oscilloscope is working, but a nice one with a wooden cabinet went for a stunning $1,175 in 2/05 and one sold for $1,025 in 6/09.

Marantz 20B search eBay
Although very similar to the Model Twenty, the 20B is even more rare today. Our contributor Tim "worked at a dealership that sold many different models of Marantz tuners. The favorite Marantz tuner of virtually everyone who worked for us was the 20B, and this choice encompassed the Marantz tuner range from the 10B up to the 2130. The 20B was not the most sensitive Marantz tuner we ever sold, but we thought it was the best-sounding tuner they made. Yes, we had sold 10Bs and always had one or two in for a 'tuneup' from one of our customers, but whenever we compared them, we always like the 20B better." Our contributor Brian H. adds, "The Marantz 20B is unbelieveable. The sound is almost identical to my Tandberg 3001A, in fact in some situations I prefer it over the 3001A. The 20B is most positively the best-sounding Marantz tuner, beating the 2130, 150, 125, [Esotec] ST-7 and ST-8, and even the 10B in the amount of bottom end." The 20B usually sells for $500 to $770 on eBay with a working oscilloscope, with a recent high of $899 in 6/08 and an all-time high of $1,000 in 2/05.

Marantz 23 (1973, $250) search eBay
The 23 usually sells for $50-90 on eBay but occasionally up to $125, with a recent high of $206 in 7/08 for one with a nice cabinet. In an apparent case of either mistaken identity or sheer stupidity, one eBayer hit the "Buy-It-Now" button for $250 in 2/06.

Marantz 24 search eBay
The scarce Marantz 24 is a 4-gang tuner/preamp that our panelist Ray believes has the same tuner section as the 23 tuner. Ray says, "It's OK but not a DX machine. You hear a lot about the warm Marantz sound of that era, but I would rather call it lifeless. That could be the line section of the preamp, though. It measures great but just sounds flat." Our contributor Tim agrees that the 24 "had the same tuner as the Model 23 tuner with an OK but not great preamp." The 24 usually sells for $100-180 on eBay, with a recent low of $67 in 3/08 and a high of $275 in 6/09. [RFM]

Marantz 104 (1976, $170, photo) search eBay
The 104 has 3 gangs for FM and 2 gangs for AM. It usually sells for $50-100 on eBay, but up to $175-200 is not uncommon for nice ones with wooden cabinets or rack handles.

Marantz 105 (1973, $170/orig $150, photo) search eBay
On eBay, the 105 can sell for anywhere from $45-50 (one even inexplicably closed at $10 in 8/05) or up to $140-150 for nice ones, or even higher: would you believe $271 and $259 for two nice 105s with wooden cabinets in 4/06?!

Marantz 105B (1974, $170, photo) search eBay
The 105B usually sells for $50-110 on eBay, with a low of $32 in 8/05 and a bizarre high of $275 in 11/04 for one with a wooden cabinet. The more recent high was $220 in 5/06.

Marantz 110 (1971, $180, photo1, photo2) search eBay
The 110 usually sells for $70-120 on eBay, with a recent low of $51 in 10/08 and a recent high of $150 in 6/09. Occasional sales for over $200 are possible for 110s with woodencabinets.

Marantz 112 (1975, $220, photo) search eBay
The 112 usually sells for $90-150 on eBay, with higher prices possible for nice ones with wooden cabinets. The recent low was $56 in 5/09 and the all-time high was $250 in 9/07.

Marantz 115 (1973, $250, photo) search eBay
The 115 usually sells for $100-150 on eBay, with a recent low of $50 in 6/08 and occasional highs of $235-275.

Marantz 115B (1974, $300, photo) search eBay
The 115B boasts a very unusual feature: a continuously variable muting knob. The 115B usually sells for $145-240 on eBay, but as low as $75 and over $300 are both possible. The record high was an astonishing $510 in 8/08.

Marantz 120 (1971, $429, photo, schematic) search eBay
The 120, a well-regarded tuner with an oscilloscope, had 5 gangs and 8 ceramic filters (but see the comments by Hank and Bill in the 120B writeup below). It usually sells for $275-450 on eBay, but $280-290 is possible. Those with wooden cabinets sell for the higher prices, on average, and one with a cabinet and manuals sold for $600 in 1/04.

Marantz 120B (1974, $550, photo) search eBay
Like its predecessor, the 120, the Marantz 120B had 5 gangs and 8 ceramic filters, and we initially thought it might make a good tuner for DXing if modified with new matched, narrow filters for improved selectivity. However, our contributor Hank says, "In the case of the Marantz 120B it would probably matter little if the filters were 'hand selected,' because they are not properly terminated into a 330 Ohm load. Bill Ammons has worked on two of these tuners for me and had to make significant changes to the IF board. I was lured into thinking, 'Wow! Eight filters! Must be *really* selective!' Alas, I'm afraid it ain't necessarily so. And I'll bet $100 those eight [original] filters were NOT 'hand selected' in any event." Bill comments, "In stock form [and 30 years after it was manufactured - Editor] the 120B is not very good, and does not come close to meeting any of its published specifications. After reworking the entire IF strip and upping some parts values, I was able to get the distortion under 0.5% and achieve 40 dB of stereo separation at 1 kHz. A third unit sitting here awaiting alignment came in at 2.0% THD and 13 dB of stereo separation after an inital tweaking!"

Hank adds, "I have made extensive use of three unmodded 120Bs and two Marantz 150s. In sensitivity, selectivity and audio quality, both 150s unambiguously creamed the three 120Bs. Marantz's published specs on both tuners may have been essentially the same but my experience with both was very different. All things considered, I think the 120B must be considered a design failure as evidenced by the fact that in the 150, Marantz chucked those 8 ceramic filter and went back to an LC IF. Given their greater expense versus ceramic filter IFs, I think Marantz was as much as admitting that the 120B had problems." Our contributor David Rich notes that the 120, 120B and 150 all have one RF stage which is single-tuned at the antenna and triple-tuned at the RF out. The 120B's usual sale price range on eBay is $300-500, with a low of $141 in 4/09 and an all-time high of $635. Good condition (of course, the oscilloscope must work properly) and a wooden cabinet seem to create frenzied bidding by collectors.

Marantz 125 (1975, $340, photo, review page 1, page 2, page 3) search eBay
Our contributors Tim and Ann tell us: "The 125 is the same tuner as the 150 sans the scope, scope inputs and scope controls. And neither tuner has variable selectivity so if you can do a filter change on this tuner, you're stuck with whatever filter slopes you choose when you have the filters installed. We owned a 125 years ago and liked it, but we didn't have any selectivity issues and did not need to DX, and we thought it sounded particularly good on live studio broadcasts. But we also brought home an Accuphase T-100 and T-101 to compare and both the Accuphase Tuners sounded a bit better and were a bit more sensitive on weak stations we generally didn't listen to (and a whole lot more expensive!). We also tried a Kenwood KT-8005 and a Kenwood KT-8007 and liked the sound of the Marantz 125 better. Finally, the dial lights on the 125 and the 150 are notorious for burning out and they are soldered in and are a pain in the butt to replace. You have to be careful not to burn the plastic dial with the soldering iron when removing the bad lights and soldering in the new lights." Another tuner fan reported that the lights in some 125s (later production runs?) may have been clipped in, but we have not confirmed this. The 125 used LC filters, rather than ceramics, and would not be suitable for a filter mod to increase selectivity. The 125 is very common on eBay, usually $150-200 or higher in good condition or $80-120 in fair-to-poor condition. If in excellent condition and with a wooden cabinet, the collectors salivate and up to $320-400 is possible.

Marantz 150 (1975, $600, photo) search eBay
The 150 is basically similar to the 125, with the addition of an oscilloscope. Our contributor Hank shares the following: "I have a Marantz 150 that is a wonderful tuner. I found a fellow on eBay selling NOS CRT's so that was installed. The internal balun was removed (along with that absurd -20dB attenuator switch), and a chassis-mount female F-connector installed with mini 75 Ohm coax from it to the first RF amplifier. All power supply capacitors were replaced with higher cap/voltage devices. All electrolytic caps were replaced. Higher cap/voltage audiophile-grade caps went into the audio circuits. The tuner was thoroughly cleaned (all switches now work like new), tuning cord replaced, and the tuner was aligned. While not the most selective tuner I own, it is very sensitive, impervious to overload, has a very broad stereo soundstage and is easy to listen to for extended periods--the test most important to me." See also Hank's comments in the Marantz 120B writeup above. The 150 used LC filters, rather than ceramics, and would not be suitable for a filter mod to increase selectivity. Our contributor David Rich notes that the 150, like the 120 and 120B, has one RF stage which is single-tuned at the antenna and triple-tuned at the RF out.

Our contributor Dan D. says, "For years, I felt that the Marantz 150 was a rather mediocre unit performance-wise compared to the Kenwood, Aiwa and Sansui, debating whether or not to let it go and move on to something newer (digital). Then out of pure curiosity I decided to spend a few and sent it in for an alignment and bulb replacement. What I got back was quite different. I was rather unprepared for the transformation. It was brilliant, and most definitely a keeper." Our contributor Dave O. had similar results with his 150: "I thought it was really average unil I aligned and re-capped it. Then, WOW! Of course, there's no way to change the bandwidth in it without completely replacing the IF strip, but the compromise they struck is just perfect for my needs." The 150 usually sells for anywhere from $470-715 on eBay, but a wealthy or ignorant newbie won one with an inexplicable bid of $1,125 in 11/03, and a nice one with a cabinet went for $1,034 in 12/04.

Marantz 2020 (1978, $180, normal, brown) search eBay
The low-end 2020 can sell for anywhere from $25 to over $100 on eBay.

Marantz 2100 (1977, $250, photo, full system) search eBay
The 2100 is an attractive tuner that somewhat resembles the 2130 cosmetically, but it only has 3 gangs and 3 filters so its performance is not comparable. The 2100 has only one IF setting and has poor adjacent channel selectivity in stock form because its stock filters are very wide. Our panelist Eric also noted rolled-off highs. In short, buy it for looks, not performance. Many people who presumably have not read this page seem to think that the 2100 is a better tuner than it is, and will drastically overpay for it: it occasionally sells for up to $200, and one mint 2100 sold for an astounding $355 in 6/03. Two crazed bidders ran one up from $40 to $280 in 11/04. More savvy buyers with a little patience, recognizing that the 2100 is extremely common, can easily find one for $100 or less on eBay (with a low of $20 in 12/04). Expect to pay more, up to around $150, for a 2100 with the rare rack handles. [EF]

Marantz 2110 (1978, $380, photo) search eBay
If you must have a Marantz tuner with an oscilloscope but find the 2130 too pricey, perhaps the similarly beautiful 2110 will suffice, but be aware that it is (surprisingly) only a 3-gang tuner! The 2110 usually sells for $220-375 on eBay, but one went for just $167 in 5/04 and $400+ is possible for a mint one (the alltime high was $510 in 2/06 and the recent high was $438 in 6/09).

Marantz 2120 (1977, $320, photo) search eBay
The 2120 has 4 FM gangs (2 AM gangs) and 4 filters, wide/narrow IF bandwidth settings, and pretty good published specs. Our contributor Larry speculates that the 2120's circuitry may be mostly identical to the 2110's (except for the lack of an oscilloscope), and it looks great, but it's "not a 2130 by a long shot." The 2120 usually sells for $150-240 on eBay, but nice ones can go for over $300.

Marantz 2130 (1978, $600, photo, schematic) search eBay
One of the all-time classic tuners, the 2130's art-deco styling, cool blue lights and built-in oscilloscope might compel one to just sit and stare at it in the dark. The 2130 has 5 gangs for FM and 3 for AM, variable and defeatable muting, a quartz lock circuit and an MPX noise filter. The MPX filter is seldom needed because the tuner is so quiet, even on weak signals. The 2130 has an unusual filter scheme, with two wide and one narrow (180 kHz) 3-pin ceramic filters, two "SAW" (Surface Acoustic Wave) filters like those used in some of the top Kenwoods, and a 4-pole LC filter block that we suspect is used in non-filtering areas in the detector and limiter. (F201=LC, F202=SAW, F203=ceramic, F204=ceramic, F205=SAW, F206=ceramic.) Even an amateur who understood the schematic would find the 2130 difficult to modify because of how the multiple circuit boards are laid out. Our contributor David Rich observes, "The 2130 has two RF stages and a very low input sensitivity. I think the marketing department drove that decision" - perhaps at the cost of increased susceptibility to mixing products when faced with strong signals.

In stock form, the 2130 has better selectivity in the wide IF bandwidth mode than most tuners and decent adjacent-channel selectivity in narrow mode, comparable to that of a Kenwood KT-8300. The 2130 would probably be one of the definitive tuners for DXers or audiophile/DXers, with performance on the level of a modified Kenwood 600T or KT-917, if modified by a professional. The 2130 usually sells for $650-1,000 on eBay, but higher is possible. Several have sold for $1,225-1,450 over the years, and one, with rare rack handles, went for a mind-boggling $1,825 in 7/02. Cosmetically challenged 2130s can sell for as little as $350-425. One stupid seller priced his 2130 with one missing knob at just $50 "Buy-it-Now" in 9/04, but then packed it equally stupidly and it was damaged in shipping! More information on the 2130 is available at Ben Blish's classic-audio.com. See how one 2130 sounded compared to other top tuners on our Shootouts page. The 2130e is a European model, identical to the 2130 except without Dolby FM circuitry. [EF][JR]

Marantz Esotec ST-5 search eBay
The ST-5 was similar to the ST-500, reviewed below. They are almost identical cosmetically, except that the ST-5 has round pushbuttons on the front rather than the rectangular pushbuttons on the ST-500. Apparently some ST-5s don't say "Esotec," and those tend to sell for lower prices on eBay. Two with the Esotec name sold for $187 in 10/06 as two bidders ran up the price from $98, and $99 in 4/08. We'll have more information on the ST-5 shortly.

Marantz Esotec ST 7 (1979, $650) search eBay
and
Marantz Esotec ST-8 (1979, $750) search eBay
These rare tuners were part of Marantz's high-end "Esotec" series. The ST 7 (without hyphen) was a black tuner with rack handles, while the ST-8 (with hyphen) had an anodized gold front panel and was sold with a walnut cabinet. We believe that they were otherwise identical, and very similar to the Marantz 2130, with 5 FM gangs and 3 AM gangs. Some minor differences were round oscilloscopes in the ST 7 and ST-8, vs. a square one in the 2130; fixed and adjustable audio outputs in the ST 7 and ST-8, vs. fixed only in the 2130; and the Dolby FM circuitry (irrelevant today) in the 2130, but not in the ST 7 or ST-8. According to a Marantz advertisement, "The ST 7 is equipped with a low noise dual-gate MOSFET sensitive FM front end. To achieve first class selectivity and minimal distortion, the ST 7's dual IF circuit for FM reception is fitted with LC filters and a SAW (Surface Acoustic Wave) filter [the 2130 had two SAW filters - Editor]. Its other main features are: quartz locked gyro touch tuning; FM IF band width selector; adjustable muting; audio level control; 400 Hz tone generator for recording calibration." The ST 7 usually sells for $800-936 on eBay, with a recent low of $665 in 11/06. A non-working (!) ST-8 sold for $1,225 in 2/04, a British one went for $1,248 in 9/04, one with burned-out dial lamps sold for a relatively rational $608 in 5/06, and two with wooden cabinets fetched $810 in 10/07 and $717 in 4/09.

Marantz ST-17 a/k/a ST-17U (2005, $749/orig 1998, $650) search eBay
Our contributor Ryan posted a surprisingly positive review of the 4-gang ST-17 in our FMtuners group. Ryan tells us that the ST-17 uses bona fide Audiophile capacitors in its audio section ("ridiculously expensive ones, Elna Cerafine") and "sounds good too, after a major realignment, and looks at home with modern audiophile gear." Our panelist Ray is also a fan: "The ST-17 is very solidly constructed and quite large at 18" wide x 3.5" high x 12" deep. Though a digitally tuned unit, it features the vintage Marantz signature horizontal thumb-wheel for station selection, nice touch. After a tour through the schematic [our panelist] Bob reported the following: 'No details on the RF front end in the schematic, but I did notice it has attenuation for strong RF signals, good for people who have local overload problems. The IF path looks good, nothing fancy, with 3 discrete bipolar transistor differential amps and 4 ceramic filters, 2 wide and 2 narrow. The detector is a typical quad type working with the LA1266 FM IF chip, followed by a 4-pole anti-birdie filter, which maybe now we should also call anti-HD interference. Then the LA3410 MPX chip, with switchable de-emphasis implemented via feedback from the chip's output op-amps. These feed the highlight of the tuner, the HDAM output circuit. Each channel of these output amps consists of 8 discrete bipolar transistors with a differential front-end amp and balanced push-pull outputs. The nice thing is that there are no coupling caps involved in implementing the amp circuit, unlike earlier discrete output designs. This stage is followed by muting transistors and the output filter, likely a combination 15 kHz lowpass and 19/38 kHz notch.'

"The four CFs Bob described are premium 220 kHz GDT types in the Wide mode with a 230 kHz and 280 kHz normal type added in Narrow. The front end is a 4-ganger. I measured the de-emphasis response at an exemplary -0.30 dB at 10 Hz, -0.05dB at 20 Hz and then flat to within +/- 0.20 dB all the way up through 15 kHz... as good as I can measure. One of the things I quickly noted upon first listen was an unusually deep and authorative bass, and so it measures. This is as good-sounding a stock tuner as has ever made it to 'Ray's room' - no mod plans brewing here. I find the ST-17 to be a fine tuner with decent sensitivity and selectivity and great sound and it is certainly not 'sparrow feed.'" Our contributor Tim adds, "The ST-17 is the best-sounding, stock, non-aligned tuner I've heard yet in my system." The ST-17 usually sells for $170-310 on eBay. [RFM]

Marantz ST-46 ($250) search eBay
We hope to add a photo and some information on the not-too-rare, basic black, digital display, remote-capable, FM-AM ST-46 eventually. The ST-46 has 30 station presets and its "station naming function allows a user-defined five-character name to be assigned to each preset station." The ST-46 usually sells for $25-50 on eBay, but occasionally over $80 (presumably these overpayments are due to lack of information, which we aim to correct).

Marantz ST-50 a/k/a ST-50U search eBay
We don't know anything about the ST-50 except that it has wide and narrow bandwidth settings, which is enough for us to speculate that it may be halfway decent. It can be found in silver or black finish and looks much sharper and better constructed than most later-era plasticky black digital Marantzes. Some (all?) ST-50s say ST-50 on the front panel and ST-50U on the back-panel label. The ST-50 doesn't seem to be nearly as rare as some of the others so perhaps someone will write and tell us about it. The ST-50 usually sells for $40-60 on eBay, with record lows of $10 in 12/07 and 9/08.

Marantz ST-53 a/k/a ST-53U ($300) search eBay
We know nothing whatsoever about the very rare ST-53. Any help? It shows up about once a year on eBay and sells for $20-50.

Marantz ST-54 (1989, $430/gold $500/orig $319, photo) search eBay
The ST-54 is an attractive digital tuner with a fine-tuning knob and fine-tuning memory on presets. It was manufactured with a black, gold or Champagne color cabinet, and with or without rosewood-look side panels. Stereophile's original review called the ST-54 "one of the most sensitive tuners manufactured" at that time. Its selectivity is normally just average, but a filter mod might transform it into a good DXing tuner, particularly given its fine-tuning capability. An unswitched accessory outlet on the back panel is a nice feature. We don't know if all ST-54s had switchable voltage and a switch to select European or U.S. tuning increments and de-emphasis, but at least some did. The ST-54 usually sells for $40-75 on eBay, with a low of $10 in 3/09 and a remarkable high of $280 in 1/06. New-old-stock ST-54s sold for $210 in 10/06 and $170 in 12/07.

Marantz ST-55 a/k/a ST-55U ($300) search eBay
We know nothing whatsoever about the ST-55, which may be the rarest of these obscure black digital Marantzes. The only one we've ever seen sold for $34 on eBay in 4/08.

Marantz ST-59 a/k/a ST-59U search eBay
We don't know anything about the rare ST-59 but speculate (without much foundation) that it may be similar to the ST-54. It can sell for $20-80 on eBay, with a low of $10 in 8/08, but two losers bid up the price of one from $102 to $257 in 7/07.

Marantz ST-64 search eBay
Like the ST-59, we don't know anything about the very rare ST-64, but guess (wildly) that it may be similar to the ST-54. Our U.K. contributor Paul E. tells us about the presumably similar ST-64L: "I have a champagne Marantz ST-64L with longwave. When I first bought it I was disappointed that the wide/narrow bandwidth switch did not seem to make much difference. When I looked inside I found that it has 4 ceramic filters, all with a 280 kHz bandwidth. Two of them are used in wide, and a further 2 are inserted in narrow. It is very easy to replace the 2 filters used for narrow if you want (I did!) as you can unscrew the base plate as well as the top. It has fine tuning which is very useful, if you install ultra narrow filters. The front end looks the same as in my Technics ST-S505 (Mitsumi, I think). The ST-64L has 16 memories: 8 on FM, 8 shared on mediumwave and longwave. Is it worth $50? Well I paid 25 UK pounds (about $50) and that seems cheap to me!" The only ST-64 we ever recall seeing in the U.S. sold for $61 in 8/04.

Marantz ST-74 search eBay
Another Marantz mystery. We only recall seeing two ST-74s on eBay, which sold for $49 in 2/07 and $34 on 12/08.

Marantz ST-300 search eBay
The ST-300 was apparently the baby in the ST-300/ST-400/ST-600 group. This is a "placeholder" listing, but we'll be posting a photo and some information on it eventually. The ST-300 usually sells for $35-80 on eBay and this listing should not be construed as a recommendation. The all-time (bizarre) high was $217 in 9/08 as two crazed bidders ran it up from $50.

Marantz ST-400 search eBay
Our contributor Warren M. tells us that the very common ST-400 was the middle model in the ST-300/ST-400/ST-600 group, which came out after Superscope took over the Marantz name. We'll be posting a photo and more information on it eventually. The ST-400 usually sells for $40-80 on eBay, with a low of just $15 in 6/06 and a high of $127 in 4/06. Two rare ST-400s with rack handles went for $132 in 8/05 and $78 in 5/07.

Marantz ST-450 search eBay
This is a "placeholder" listing, but we'll be posting some information on the ST-450 eventually. The ST-450 usually sells for $40-80 on eBay, with a low of $25 in 1/08 and a high of $101 in 2/05.

Marantz ST-500 search eBay
Here's a review from Bill Ammons: "The ST-500 is a small digitally synthesized tuner from the mid-1980s with a light gold finished aluminum front panel. It has a digital frequency display and dual IF bands. The front end is a 4-gang MOSFET design with a bipolar mixer. The IF chain consists of two 280 kHz filters in the Wide mode. The narrow IF is switched in between the first and second filter stages and consists of one 230 kHz filter and a tuned 10.7 MHz can. The ST-500 uses an HA 11225 quad detector IC which feeds a Toko 4437 stereo demod IC. The audio output is a Toko 4438 IC. The selectivity is limited by only having a total of 3 ceramic filters in the IF even in the Narrow mode. I did modifiy the Narrow IF by using a 3-filter IF FILTER ADDER PCB and one 150 kHz and two 230 kHz filters. That greatly improved narrow selectivity. There is a stereo separation control for both Wide and Narrow IF modes. When modified, the ST-500 will pick up about 90% of what my modified Pioneer TX-9500II will grab." Our contributor Tim has an ST-500 and hasn't listened to it enough to comment on its sound quality, but he notes that it is significantly less sensitive than many of his other tuners. Tim adds that the ST-510 was the military/European version of the ST-500. Inexplicably, the ST-500 often sells for a fraction of what the similar ST-5 usually brings on eBay: despite a high of $100 in 8/06 and occasional sales in the $30-70 range, $10 or less for the ST-500 is not uncommon.

Marantz ST-530 ($265) search eBay
This is a "placeholder" listing, but we'll be posting some information on the ST-530 eventually. The ST-530 usually sells for $10-25 on eBay and this listing should not be construed as a recommendation. The all-time high was $113 in 8/08, as two bidders ran it up from $19.

Marantz ST-600 search eBay
According to our contributor Warren M., the very rare ST-600 was the top model in the ST-300/ST-400/ST-600 family, which came out after Superscope took over the Marantz name. The ST-600 had an oscilloscope and looks like a good tuner, but we don't know what it has under the hood. We'll be posting a photo soon and hope to have more information on it eventually. An ST-600 sold for $222 on eBay in 7/07.

Marantz ST6000 (2000, $300, photo, service manual 1, 2) search eBay
and
Marantz ST6000P (2002) search eBay
The ST6000/6000P is a black AM-FM digital tuner that was available either with (the "P" model) or without rack-mount handles. We don't know if there are any other differences between the two versions. Like its much more expensive competitors, the Fanfare FT-1A and FTA-100, the lightweight ST6000/6000P is very attractive and has wide and narrow IF bandwidth settings. It has the electronic equivalent of 4 gangs and 4 ceramic filters. The ST6000 has a clean sound, with decent bass, and some nice features like a built-in timer, dual antenna inputs (one normal 75-Ohm jack and one Euro or PAL jack), and a jack for a remote control (which we did not test). Our panelist Eric tested an ST6000 that was modified with narrow filters installed, and its selectivity was tough to beat. Eric also tested a stock ST6000 that was sensitive and had good (but not Onkyo-caliber) selectivity. Overall, the recent Fanfare models may be better tuners but when new, were not worth five times the price of a new ST6000. Sale prices for the ST6000 on eBay have inexplicably trended down from $120-185 in 2006, to mostly $50-100 in 2007, to mostly $40-60 in 2008-09. The record low was $25 in 6/08 and the recent high was $125 in 2/09.[EF]